The whelmed podcast (located at the nigh-perfect url http://crashingthemode.com/) is basically "Buffering the Vampire Slayer," but for Young Justice. I've just started in on the beginning of the show, and it's great; if you like podcasts where pop culture love and gaming overlap and/or intersect, I recommend it.
But here's an additional BONUS: the podcast crew recently recorded a session of Masks, GM'd by Brendan Conway (the game's author), in which they play characters from the show in a scenario set in the five years between seasons 1 and 2 of YJ. The people playing these characters are note. perfect. in their protrayals (Kid Flash and Superboy are particular stand-outs), and Brendan does a fantastic job of introducing, integrating, and best-of-all explaining the rules as they go.
If you're looking for an AP recording that works as a primer/introduction to the Masks rules, and want the added bonus of seeing the game presented via characters with which you're probably already very familiar, I can't recommend these recordings enough.
Update: There are also pre- and post-game talks with Brendan, which are pretty illuminating.